import org.bouncycastle.asn1.cms.EncryptedContentInfo; //导入依赖的package包/类
public CMSTypedStream getContentStream(InputDecryptorProvider inputDecryptorProvider)
    throws CMSException
{
    try
    {
        EncryptedContentInfo encContentInfo = encryptedData.getEncryptedContentInfo();
        InputDecryptor decrytor = inputDecryptorProvider.get(encContentInfo.getContentEncryptionAlgorithm());

        ByteArrayInputStream encIn = new ByteArrayInputStream(encContentInfo.getEncryptedContent().getOctets());

        return new CMSTypedStream(encContentInfo.getContentType(), decrytor.getInputStream(encIn));
    }
    catch (Exception e)
    {
        throw new CMSException("unable to create stream: " + e.getMessage(), e);
    }
}
 

import org.bouncycastle.asn1.cms.EncryptedContentInfo; //导入依赖的package包/类
private ASN1Primitive createDERForRecipient(byte[] in, X509Certificate cert) 
    throws IOException,  
           GeneralSecurityException 
{
    
    String s = "1.2.840.113549.3.2";
    
    AlgorithmParameterGenerator algorithmparametergenerator = AlgorithmParameterGenerator.getInstance(s);
    AlgorithmParameters algorithmparameters = algorithmparametergenerator.generateParameters();
    ByteArrayInputStream bytearrayinputstream = new ByteArrayInputStream(algorithmparameters.getEncoded("ASN.1"));
    ASN1InputStream asn1inputstream = new ASN1InputStream(bytearrayinputstream);
    ASN1Primitive derobject = asn1inputstream.readObject();
    KeyGenerator keygenerator = KeyGenerator.getInstance(s);
    keygenerator.init(128);
    SecretKey secretkey = keygenerator.generateKey();
    Cipher cipher = Cipher.getInstance(s);
    cipher.init(1, secretkey, algorithmparameters);
    byte[] abyte1 = cipher.doFinal(in);
    DEROctetString deroctetstring = new DEROctetString(abyte1);
    KeyTransRecipientInfo keytransrecipientinfo = computeRecipientInfo(cert, secretkey.getEncoded());
    DERSet derset = new DERSet(new RecipientInfo(keytransrecipientinfo));
    AlgorithmIdentifier algorithmidentifier = new AlgorithmIdentifier(new ASN1ObjectIdentifier(s), derobject);
    EncryptedContentInfo encryptedcontentinfo = 
        new EncryptedContentInfo(PKCSObjectIdentifiers.data, algorithmidentifier, deroctetstring);
    EnvelopedData env = new EnvelopedData(null, derset, encryptedcontentinfo, (org.bouncycastle.asn1.ASN1Set) null);
    ContentInfo contentinfo = 
        new ContentInfo(PKCSObjectIdentifiers.envelopedData, env);
    return contentinfo.toASN1Primitive();        
}
 

import org.bouncycastle.asn1.cms.EncryptedContentInfo; //导入依赖的package包/类
public CMSAuthEnvelopedData(ContentInfo contentInfo) throws CMSException
    {
        this.contentInfo = contentInfo;

        AuthEnvelopedData authEnvData = AuthEnvelopedData.getInstance(contentInfo.getContent());

        this.originator = authEnvData.getOriginatorInfo();

        //
        // read the recipients
        //
        ASN1Set recipientInfos = authEnvData.getRecipientInfos();

        //
        // read the auth-encrypted content info
        //
        EncryptedContentInfo authEncInfo = authEnvData.getAuthEncryptedContentInfo();
        this.authEncAlg = authEncInfo.getContentEncryptionAlgorithm();
//        final CMSProcessable processable = new CMSProcessableByteArray(
//            authEncInfo.getEncryptedContent().getOctets());
        CMSSecureReadable secureReadable = new CMSSecureReadable()
        {

            public InputStream getInputStream()
                throws IOException, CMSException
            {
                return null;
            }
        };

        //
        // build the RecipientInformationStore
        //
        this.recipientInfoStore = CMSEnvelopedHelper.buildRecipientInformationStore(
            recipientInfos, this.authEncAlg, secureReadable);

        // FIXME These need to be passed to the AEAD cipher as AAD (Additional Authenticated Data)
        this.authAttrs = authEnvData.getAuthAttrs();
        this.mac = authEnvData.getMac().getOctets();
        this.unauthAttrs = authEnvData.getUnauthAttrs();
    }